powerpc/vio: use strcpy in modalias_show

commit 411cabf79e684171669ad29a0628c400b4431e95 upstream.

Commit e82b89a6f19bae73fb064d1b3dd91fcefbb478f4 used strcat instead of
strcpy which can result in an overflow of newlines on the buffer.

Signed-off-by: Prarit Bhargava
Cc: benh@kernel.crashing.org
Cc: ben@decadent.org.uk
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index cfe0069..fcf89bf 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -1342,12 +1342,12 @@
 
 	dn = dev->of_node;
 	if (!dn) {
-		strcat(buf, "\n");
+		strcpy(buf, "\n");
 		return strlen(buf);
 	}
 	cp = of_get_property(dn, "compatible", NULL);
 	if (!cp) {
-		strcat(buf, "\n");
+		strcpy(buf, "\n");
 		return strlen(buf);
 	}